For six years I experimented to try and make a slingbow, that was affordable, durable (no whisker biscuit), reliable and accurate. After about 36 design changes I watched Jorg's Mantis Slotbow video. It finally solved the nagging reliability issue I had with my design. * I liked the sound of Mark XII versus Mark XXXVI.
The Mark XII is based on the Marksman model 3040. The wrist support was replaced with a length of 1/4" fuel line. The arrow rest is made from 1/2" thick HDPE. The mounting bracket consists of: 2- 1/8" thick X 1" wide X 2 1/2" long aluminum plates, a 1/4" diameter machine bolt with washer, lock washer, and butterfly nut. The HDPE is slightly softer than the carbon arrows I shoot. 1/8" wide denim strips with double sided carpet tape solved the wear problem and resulted in a quiet draw and release. It costs about $30.00 to make. It is accurate and fun to shoot.
Mr. Sprave: Thank You Very Much!